1. Field of the Invention
The present invention relates to a method of handling a diesel particulate filter.
2. Description of the Related Art
Exhaust gas (hereinafter, simply referred to as xe2x80x9cexhaustxe2x80x9d) of a diesel engine includes a large amount of granular matters when an air cleaner is clogged and when the engine is in rapid acceleration. The granular matters are constituted by C (free carbon by incomplete combustion, so-to-speak black smoke or soot) and SOF (Soluble Organic Fraction: uncombusted portion of diesel fuel and lubricant) both of which are pollution causing matters. Hence, there is an engine mounted with a filter for removing diesel particulate at an exhaust pipe of the engine for removing the granular matters from exhaust. Further, the granular matters are so-to-speak PM (Particulate Matters: hereinafter, simply referred to as xe2x80x9cPMxe2x80x9d). Further, the filter for removing diesel particulate is so-to-speak DPF (diesel particulate filter: hereafter, simply referred to as xe2x80x9cDPFxe2x80x9d).
Here, residuary substances produced by combustion of caught PM are deposited on a PM catching face of DPF and therefore, the catching function of DPF is deteriorated. Hence, deteriorated DPF is removed from the engine and washed and remounted to the engine or interchanged by a new article. Unnecessary DPF is scrapped.
Meanwhile, a direction of mounting DPF to the engine is normally determined as can be exemplified in other filters such as a fuel filter, a lubricant filter, a working fluid filter and an air cleaner. Further, DPF is not a simple filter and catcher but includes various kinds of useful noble metals for constituting oxidation catalysts. Therefore, there are the following drawbacks.
(1) A flow rate of exhaust stays the same before and after DPF and therefore, it is preferable to constitute DPF to be able to use revertedly. In this case, even when a reversing type DPF is reclaimed (washed as mentioned above) until DPF cannot be used again and remounted to the engine, the remounting is carried out manually. Therefore, in remounting, the DPF may be mounted in a direction the same as that in mounting the DPF at preceding time by mistake or ignorance. Further, when such an erroneous operation is repeated, the remounted DPF cannot achieve an expected value of the catching function (service life). Further, a time period of making the DPF unreusable is shortened. That is, useful metals are wasted and the effect of using the DPF is halved.
(2) When the DPF is scrapped by interchanging the DPF by a new article although the DPF can be washed and remounted, limited resources are wasted.
(3) It is desired to recover DPF to be scrapped efficiently to thereby recover and reuse useful metals.
In view of the above-described drawbacks and future perspective, it is an object of the invention to provide a method of handling DPF (Diesel particulate Filter) capable of resolving at least one thereof.
In order to achieve the above-described object, according to an aspect of the invention, there is provided a method of handling a diesel particulate filter wherein the diesel particulate filter mounted to a diesel engine for catching particulate matters included in an exhaust gas is reclaimed until being brought into a nonreusable state and remounted to the engine at least by one time, and in mounting the filter, the filter is mounted such that the filter is mounted in a direction reverse to a direction of mounting the filter at a preceding time.
Further, in remounting DPF, it is preferable to provide a mark indicating a direction of mounting in remounting the filter at a current time to DPF.
Further, it is recommendable that it is determined that the filter is nonreusable by a predetermined number of remounting the same DPF or at least one of predetermined fluid pass resistance and fluid pass flow rate of DPF.
According to the above-described constitution, DPF is mounted revertedly in the direction reverse to the mounting direction at the preceding time at each time of remounting DPF and therefore, an expected value (service life) of a catching function of remounted DPF can be ensured. Further, a time period reaching a nonreusable state of the filter is prolonged. That is, useful metals are not wasted and the effect of using DPF can maximally be achieved. Since the determination of nonreusableness is made clear, DPF to be scrapped can efficiently be recovered and useful metals can be recovered and reused.